In the essay-writing process, there are several steps. Some of these are only available with take-home essays, or essay-like projects.

This is also a recursive process. The word "recursive" means that the process circles back on itself. It isn't a straight line: do A, then do B, then do C... In writing an essay, there are start and end points, but many of the middle steps can overlap, happen more than once, switch around, and so on.
Here's an illustration:recursive2.jpg

A timed essay (or in-class essay) has less of the around/back and forth/re-do/overlap because there is simply a shortage of time to do it in. DON'T get bogged down in the middle and run out of time to complete an in-class essay!

Having the extra time to restructure, rewrite, fiddle with, and get feedback on an essay is one reason that students generally do MUCH better on project-like, take-home essays than they do on in-class essays. DON'T lower your mark by leaving the whole thing until the last minute and robbing yourself of the opportunity to improve through this recursive process!

HINTS:
1. If the essay is part of a test or exam, read (and dissect/analyse) the essay question(s) FIRST, before starting the test. That way, some of the pre-writing can happen in the back of your head while you write the rest of the exam. There might also be information or ideas in other parts of the test that spark support ideas for you.
2. On a timed essay, you won't have time for most of the steps. Pare it down to planning, writing, and editing/proofreading/revision. Alternatively, you might have done a lot of the "prewriting" stuff in class and be allowed to bring notes to support you.
3. Double space! It will give you room to go back and add words, phrases, or even whole sentences. If you need to add more than that, put an asterisk (*) on the page, and then write the extra part after the end of your essay, or on a separate sheet, after a matching asterisk (*). If you need to do this more than once, use a different mark each time.
4. If there are rules you must follow (like in literary writing), be sure you are very familiar with them or even jot down the rules on your planning sheet--then check to see you followed them!
5. On a timed essay, forget about a rough draft/good draft. Do more planning, less copying out.